Multiplexed signal quality display, method, and program, and recorded medium where the program is recorded

ABSTRACT

Since a multiplexed signal quality display system according to the present invention is provided with a memory means which stores measurement results obtained by measuring electric powers of signals present in all of channels within a band used and a display means which specifies a channel where the presence of a signal is predicted and which reads and displays the measured value of the specified channel, it is possible to display the waveform quality of a channel which is determined by desired Walsh code and Walsh code length.

FIELD OF ART

The present invention relates to displaying the waveform quality of amultiplexed signal such as CDMA signal.

BACKGROUND ART

The applicant in the present case has previously proposed such a CDMAsignal waveform quality measuring method as disclosed in Japanese PatentLaid Open No. 173628/1998. FIG. 7 shows an example of power display ofvarious channels as measured by the measuring method disclosed therein.

In FIG. 7, electric power W is plotted along the axis of ordinate, whilechannels CH are plotted along the axis of abscissa. In the example ofFIG. 7, Walsh code length is set at “64” to permit connection of64-channel lines, and a state is shown in which channels 0, 1, 3, 5, 7,9, 11, 13 . . . 61, and 63 are generating signals.

In the example shown in FIG. 7 it is proposed to merely fix Walsh codelength to “64” and measure the waveform quality of CDMA signal. As toWalsh length of CDMA signal presently in use in portable telephone, astandard which permits change-over to six lengths of 4, 8, 16, 63, and128 is under consideration.

A band width is set in a transmission line by Walsh code length and achannel number is determined by Walsh code. FIG. 8 shows a relationbetween Walsh code length as diffusion code length and Walsh code asdiffusion code. L=4, L=8, L=16, . . . shown in the left column representWalsh lengths. At Walsh code length L=4, a predetermined band ΔF isdivided into four and four channels of 0, 1, 2, 3 are allocated thereto.The channel numbers 0–3 of the four channels are given in terms of Walshcode numbers 0, 1, 2, and 3.

As is seen from FIG. 8, as Walsh code length becomes larger, the numberof employable channels increases in a doubly increasing relation and anemployable band width becomes narrower in decrements of ½. From thisrelation it will be seen that a short Walsh code length is allocated toa telephone set which handles a large volume of data to be transmitted,while a long Walsh code length is allocated to a telephone set whichhandles a small volume of data. In FIG. 8, Walsh code lengths 64 and 128are omitted.

Thus, in the actual base station, a Walsh code length is selected fromamong six Walsh code lengths of L=4 to L=128 in accordance with thecommunication band width which the telephone set concerned requires, anda Walsh code not in use is selected and is used. Therefore, it isnecessary to test whether all the channels in all the Walsh code lengthsare in normal operation or not.

Therefore, also in the waveform quality measuring system it is necessarythat the waveform quality be measured for all Walsh codes in all Walshcode lengths.

It is an object of the present invention to provide a CDMA signalwaveform quality measuring system which, no matter which Walsh codelength defined in the standard may be used in the issuance of CDMAsignal, can determine the waveform quality of the signal.

DISCLOSURE OF THE INVENTION

The present invention as described in claim 1, is a multiplexed signalquality display system for measuring the quality of a multiplexed signalissued from a communication device wherein a band width to be used andthe number of communication channels capable of being accommodated aredetermined by a diffusion code length, the number of communicationchannels and channels to be used, which are determined by a diffusioncode length, are decided in terms of a diffusion code number affixed tothe type of the diffusion code, to effect communication while ensuringmulti-channel communication lines in one and same band, the systemincluding: a memory unit for storing measurement results obtained bymeasuring electric powers of signals present in all of the channelswithin the band used; and a display unit which specifies a channel wherethe presence of a signal is predicted and reads and displays a measuredvalue in the specified channel.

The present invention as described in claim 2, is a multiplexed signalquality display system according to claim 1, wherein the memory unitstores a phase difference or a delay difference of each the channel, andthe display unit reads the phase difference or the delay difference ofeach the channel from the memory unit and displays it.

The present invention as described in claim 3, is a multiplexed signalquality display system according to claim 1, wherein the memory unitstores an electric power of a signal and a noise component power of thesignal, and the display unit displays a graph having a lengthproportional to the values of the electric power of the signal and agraph having a length proportional to the value of the noise componentpower of the signal in such a manner that in a longitudinal direction ofone of the graphs there is disposed the other graph.

The present invention as described in claim 4, is a multiplexed signalquality display system for measuring the quality of a multiplexed signalissued from a communication device wherein a band width to be used andthe number of communication channels capable of being accommodated aredetermined by a diffusion code length, the number of communicationchannels and channels to be used, which are determined by a diffusioncode length, are decided in terms of a diffusion code number affixed tothe type of the diffusion code, to effect communication while ensuringmulti-channel communication lines in one and same band, the systemincluding: an updating unit which initializes a diffusion code lengthand a diffusion code number defined for each diffusion code length andwhich makes updating from the initialized values up to predeterminedfinal values; a diffusion code generating unit which generates adiffusion code in accordance with the diffusion code length anddiffusion code number generated by the updating unit; a demodulator unitwhich demodulates the signal in each the channel in accordance with thediffusion code generated by the diffusion code generating unit and thediffusion code length and the diffusion code number; a power coefficientcalculator which calculates a power coefficient of the signaldemodulated by the demodulator unit; a memory which stores the powercoefficient of each the channel calculated by the power coefficientcalculator in accordance with the diffusion code length and thediffusion code number; a setting unit which reads a power coefficientfrom among the power coefficients stored in the memory while specifyingdesired diffusion code and diffusion code number; a graphing unit whichconverts the power coefficient read by the setting unit into a powervalue, determines a length in Y-axis direction in accordance with thepower value, and forms a strip-like display region; an image memorywhich stores image data graphed by the graphing unit; and a calculationresult display unit which displays the image stored in the image memory.

The present invention as described in claim 5 is a multiplexed signalquality display method for measuring the quality of a multiplexed signalissued from a communication device wherein a band width to be used andthe number of communication channels capable of being accommodated aredetermined by a diffusion code length, the number of communicationchannels and channels to be used, which are determined by a diffusioncode length, are decided in terms of a diffusion code number affixed tothe type of the diffusion code, to effect communication while ensuringmulti-channel communication lines in one and same band, the methodincluding: a storing step for storing measurement results obtained bymeasuring electric powers of signals present in all of the channelswithin the band used; and a display step which specifies a channel wherethe presence of a signal is predicted and reads and displays a measuredvalue in the specified channel.

The present invention as described in claim 6 is a program ofinstructions for execution by the computer to perform a multiplexedsignal quality display process for measuring the quality of amultiplexed signal issued from a communication device wherein a bandwidth to be used and the number of communication channels capable ofbeing accommodated are determined by a diffusion code length, the numberof communication channels and channels to be used, which are determinedby a diffusion code length, are decided in terms of a diffusion codenumber affixed to the type of the diffusion code, to effectcommunication while ensuring multi-channel communication lines in oneand same band, the multiplexed signal quality display process including:a storing process for storing measurement results obtained by measuringelectric powers of signals present in all of the channels within theband used; and a display process which specifies a channel where thepresence of a signal is predicted and reads and displays a measuredvalue in the specified channel.

The present invention as described in claim 7 is a computer-readablemedium having a program of instructions for execution by the computer toperform a multiplexed signal quality display process for measuring thequality of a multiplexed signal issued from a communication devicewherein a band width to be used and the number of communication channelscapable of being accommodated are determined by a diffusion code length,the number of communication channels and channels to be used, which aredetermined by a diffusion code length, are decided in terms of adiffusion code number affixed to the type of the diffusion code, toeffect communication while ensuring multi-channel communication lines inone and same band, the multiplexed signal quality display processincluding:

a storing process for storing measurement results obtained by measuringelectric powers of signals present in all of the channels within theband used; and

a display process which specifies a channel where the presence of asignal is predicted and reads and displays a measured value in thespecified channel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing the construction of a multiplexedsignal waveform quality display system according to a first embodimentof the present invention;

FIG. 2 is a diagram showing arithmetic expressions;

FIG. 3 is a flow chart showing the operation of an updating means 34which executes initializing and updating operations of Walsh code lengthand Walsh code, and also showing in what sate arithmetic processings areperformed in various components;

FIG. 4 is a diagram showing a display screen in the first embodiment;

FIG. 5 is a diagram showing a display screen according to a modificationin the first embodiment;

FIG. 6 is a diagram showing a display screen according to a modificationin a second embodiment of the present invention;

FIG. 7 is a diagram showing a conventional display screen; and

FIG. 8 is a diagram showing a relation between Walsh code length asdiffusion code length and Walsh code as diffusion code in the prior art.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will be described hereinunder withreference to the accompanying drawings.

First Embodiment

FIG. 1 shows an example of multiplexed signal waveform quality displaysystem according to the present invention.

In FIG. 1, a frequency-diffused, multi-channel CDMA signal from a basestation is inputted through an input terminal 11 and is converted to anintermediate frequency signal by means of a down converter 12. Theintermediate frequency signal is amplified by an amplifier 13, then isband-limited by a filter 14, and is thereafter converted to a digitalsignal by an A/D converter 15. The digital intermediate frequency signalfrom the A/D converter 15 is converted to a base band signal by anorthogonal transformer 17 which includes a complementary filter,affording a base band measurement signal Z(k).

The base band measurement signal Z(k) is inverse-diffused in ademodulator 25 with a diffusion code (Walsh code) provided from adiffusion code generator 20 and bit data is demodulated for eachchannel. At the same time, amplitude a′i (i is channel number) of eachchannel is detected.

In an ideal signal generator 26, an ideal signal Ri (i is channelnumber) is produced on the basis of both bit data provided from thedemodulator 25 and diffusion code PN (Walsh code) provided from thediffusion code generator 20. Further, in accordance with the idealsignal Ri, the following expressions are calculated to generatecorrection data Ai(k), Bi(k), Ci(k), Ii(k), and Hi(k): $\begin{matrix}{{A_{i}(k)} = {a_{i}^{\prime} \cdot \left\lbrack {\sum\limits_{m = {- M}}^{M}\;{{a(m)} \cdot {R_{i}\left( {k - m} \right)}}} \right\rbrack \cdot {\mathbb{e}}^{j\;\theta_{i}^{\prime}}}} & (1) \\{{B_{i}(k)} = {\begin{Bmatrix}{{2{a_{i}^{\prime} \cdot \left\lbrack {\sum\limits_{m = {- M}}^{M}\;{{a(m)} \cdot {R_{i}\left( {k - m} \right)}}} \right\rbrack \cdot \tau_{i}^{\prime}}} +} \\{a_{i}^{\prime} \cdot \left\lbrack {\sum\limits_{m = {- M}}^{M}\;{{b(m)} \cdot {R_{i}\left( {k - m} \right)}}} \right\rbrack}\end{Bmatrix} \cdot {\mathbb{e}}^{{j\;\theta_{i}^{\prime}}\;}}} & (2) \\{{C_{i}(k)} = {\begin{Bmatrix}{{a_{i}^{\prime} \cdot \left\lbrack {\sum\limits_{m = {- M}}^{M}\;{{a(m)} \cdot {R_{i}\left( {k - m} \right)}}} \right\rbrack \cdot \tau_{i}^{\prime 2}} +} \\{{a_{i}^{\prime} \cdot \left\lbrack {\sum\limits_{m = {- M}}^{M}\;{{b(m)} \cdot {R_{i}\left( {k - m} \right)}}} \right\rbrack \cdot \tau_{i}^{\prime}} +} \\{a_{i}^{\prime} \cdot \left\lbrack {\sum\limits_{m = {- M}}^{M}\;{{c(m)} \cdot {R_{i}\left( {k - m} \right)}}} \right\rbrack}\end{Bmatrix} \cdot {\mathbb{e}}^{{j\;\theta_{i}^{\prime}}\;}}} & (3) \\{{I_{i}(k)} = {\begin{Bmatrix}{{\left\lbrack {\sum\limits_{m = {- M}}^{M}\;{{a(m)} \cdot {R_{i}\left( {k - m} \right)}}} \right\rbrack \cdot \tau_{i}^{\prime 2}} +} \\{{\left\lbrack {\sum\limits_{m = {- M}}^{M}\;{{b(m)} \cdot {R_{i}\left( {k - m} \right)}}} \right\rbrack \cdot \tau_{i}^{\prime}} +} \\\left\lbrack {\sum\limits_{m = {- M}}^{M}\;{{c(m)} \cdot {R_{i}\left( {k - m} \right)}}} \right\rbrack\end{Bmatrix} \cdot {\mathbb{e}}^{{j\;\theta_{i}^{\prime}}\;}}} & (4) \\{{H_{i}(k)} = {\begin{Bmatrix}{{2 \cdot \left\lbrack {\sum\limits_{m = {- M}}^{M}\;{{a(m)} \cdot {R_{i}\left( {k - m} \right)}}} \right\rbrack \cdot \tau_{i}^{\prime}} +} \\\left\lbrack {\sum\limits_{m = {- M}}^{M}\;{{b(m)} \cdot {R_{i}\left( {k - m} \right)}}} \right\rbrack\end{Bmatrix} \cdot {\mathbb{e}}^{{j\;\theta_{i}^{\prime}}\;}}} & (5)\end{matrix}$

The ideal signal Ri is obtained in the following manner. Demodulated bitdata of channels i provided from the demodulator 25 are inverse-diffusedwith I- and Q-side diffusion codes (Walsh codes) provided from thediffusion code generator 20, then chips “0” and “1” in the thusinversion-diffused I- and Q-side chip rows are converted to +√{squareroot over (2)} and −√{square root over (2)}, respectively to afford Iand Q signals of QPSK signal with an amplitude of 1. That is, using theideal signal Ri(k−m) with a normalized amplitude and the amplitude a′ifrom the demodulator 25, there are calculated auxiliary data Ai(k),Bi(k), Ci(k), Ii(k), and Hi(k).

The auxiliary data Ai(k), Bi(k), Ci(k), Ii(k), and Hi(k) and themeasurement signal Z(k) are inputted to a parameter estimator 27, inwhich simultaneous equations shown in FIG. 2 are solved and estimatevalues Δai, Δτi, Δθi, and Δω are obtained as solutions thereof. Usingthese estimate values, the correction parameters so far used a′i, τ′i,θ′i, and ω′ are updated as follows in a transformer 28:ω′←ω′+Δωa′i←a′i+Δaiτ′i←τ′i+Δτiθ′i←θ′i+Δθi  (6)

Then, using the thus-corrected parameters a′i, τ′i, θ′i, and ω′,correction is made for the measurement signal Z(k) and thethus-corrected measurement signal Z(k) is again subjected to theprocessings in the demodulator 25, the ideal signal/auxiliary datagenerator 26, the parameter estimator 27, and the transformer 28. Theseprocessings are carried out until the estimate values Δai, Δτi, Δθi, andΔω are optimized, that is, until reaching zero or near zero, or untilthere occurs no change of value ever with repetition. By this optimizingstep, correction is made not only for the measurement signal Z(k) butalso for the ideal signal Ri.

Therefore, an optimizing means 22 is constituted by the orthogonaltransformer 17 which includes a complementary filter, the demodulator25, the ideal signal generator 26, the parameter estimator 27, and thetransformers 28 and 29.

Correction for the measurement signal Z(k) is made as follows relativeto Z(k) of the last time:Z(k)←Z(t−τ′0)(1/a′0)exp [−j(ω′(t−τ′0)+θ′0)]  (7)

As initial values are set a′0=1, τ′0=0, θ′0=0, and ω′=0, and each timeestimate values are obtained in the parameter estimator 27, theexpression (7) is calculated with respect to new a′i, τ′i, θ′i, and ω′.That is, this calculation for correction is made for the signal inputtedto the orthogonal transformer/complementary filter 17, i.e., the outputof the A/D converter 15.

The calculation for correction may be performed for the measurementsignal Z(k) after conversion to the base band. However, this baseband-converted signal is a signal after having passed the complementaryfiler (the same pass band width as the band width of the input signal).If there is a gross frequency error, this filter processing may resultin that a portion of the signal is removed, that is, the measurementsignal to be used in parameter estimation, etc., is chipped. Therefore,the result of the frequency estimation is corrected at a stage whichprecedes the complementary filter. But the correction may be made forthe measurement signal after conversion to the base band, provided thereis used a low pass filter of a sufficiently wide band without using thecomplementary filter in the orthogonal transformer/complementary filter17.

The correction parameters a′i, τ′i, and θ′i are subjected to thefollowing conversion in the transformer 29:a″i=a′i/a′0τ″i=τ′i−τ′0θ′i=θ′i−θ′0 provided i≠0  (8)

As to the measurement signal Z(k), since the parameters of the 0^(th)channel are corrected by the expression (7), the parameters forcorrecting the 0^(th) ideal signal R₀ are normalized into the followingvalues:

a″0=1

τ″0=0

θ″0=0

The parameters for the ideal signal Ri of channels other than the 0^(th)channel are corrected by 0^(th) parameters as in the expression (8).

That is, in the first repetition in the foregoing optimization step,correction for the measurement signal Z(k) is made using the correctionparameters of the 0^(th) channel and therefore, as correction parametersused in the auxiliary data generator 26, there is used the expression(8) normalized by the parameters of the 0^(th) channel, i.e., atransformed output of the transformer 29. More particularly, thecalculations of the expressions (1) to (5) are performed usingparameters which are conceivable in the expression (8) to determineauxiliary data Ai(k), Bi(k), Ci(k), Ii(k), and Hi(k). In thiscalculation for determining auxiliary data there are used bit data andamplitude a′i, the bit data being obtained as a result of demodulatingZ(k) in the demodulator 25 after correction by the expression (7).

Thus, both corrections described above are performed every time estimatevalues are obtained from the parameter estimator 27, and the estimationof parameters is again repeated until optimization of the estimatevalues, whereupon a power coefficient ρi is calculated and determined asfollows in a power coefficient calculator 31, using measurement signalZ(k) and diffusion code (Walsh code) obtained at that instant:$\begin{matrix}{\rho_{i} = \frac{\sum\limits_{j = 1}^{N}\;{{\sum\limits_{k = 1}^{64}\;{Z_{j \cdot k}R_{i \cdot j \cdot k}^{*}}}}^{2}}{\left\{ {\sum\limits_{k = 1}^{64}{R_{i \cdot j \cdot k}}^{2}} \right\}\left\{ {\sum\limits_{j = 1}^{N}{\sum\limits_{k = 1}^{64}{Z_{j \cdot k}}^{2}}} \right\}}} & (9)\end{matrix}$The expression (9) is the same as the expression defined by the CDMAsignal measurement standard and used in the prior art.

The following calculation is performed in a transformer 32:a^=a′Δτ^i=τ′i−τ′0Δθ^i=θ′i−θ′0Δω^=ω′  (10)

The parameters a^, Δτ^i, Δθ^i, Δω^, τ^0, and the power coefficient ρiobtained in the power coefficient calculator 31 are displayed on adisplay 33.

As described above, the measurement signal Z(k) and the ideal signal Riare corrected using estimated parameters, and the estimation ofparameters is again performed using both corrected signals untiloptimization of the estimated parameters. Since all the parameters areused in this optimization, all the parameters are optimized, and afterthe optimization, the power coefficient ρi is determined using themeasurement signal, so that the power coefficient ρi can be obtainedwith a high accuracy. Other parameters are also determined with a highaccuracy because the measurement signal is included in the optimizationloop.

The multiplexed signal waveform quality display system of the firstembodiment is further provided with an updating means 34 and a memory33A.

The updating means 34 initializes the value of Walsh code length asdiffusion code length and code number of Walsh code as diffusion codeand updates the values of Walsh code length and Walsh code successivelyfrom the initialized values.

While the initialized values of Walsh code length and Walsh code areupdated successively by the updating means 34, there are calculatedwaveform quality parameters with respect to all the Walsh code lengthsand Walsh codes defined by the CDMA signal standard.

The memory 33A stores the result of the calculation. The multiplexedsignal waveform quality display system according to the first embodimentis further provided with a setting means 35, a graphing means 33B, animage memory 33C, and a calculation result display 33D.

FIG. 3 shows the operation of the updating means 34 which executes Walshcode length, Walsh code initializing and updating operations, and alsoshows in what state arithmetic processings are performed in variouscomponents.

In step SP1, Walsh code length is initialized at L=4. In step SP2, thenumber assigned to Walsh code (corresponding to channel number) is setat i=0.

In step SP3, an ideal signal Ri·L based on Walsh code length L=4 andWalsh code i=0 is produced in the ideal signal generator 26.

In step SP4, parameters are estimated in the parameter estimator 27 inaccordance with the ideal signal Ri·L and are then fed back to theorthogonal transformer 17 for optimization processing. Then, the powercoefficient ρi·L is calculated on the basis of the measurement signalZ(k) after optimization processing and the diffusion code.

In step SP5, the power coefficient ρi·L calculated in step SP4 and otherparameters ′ai·L, Δ′τi·L, Δ′θi·L, Δ′ω, τ0′ are stored in the memory 33A.

In step SP6, the value of Walsh code i is updated as i+1, then in stepSP7, the value of Walsh code length L and that of Walsh code i arecompared with each other. If both disagree, the processing flow returnsto step SP3. That is, in case of Walsh code length L=4, i=4 results fromexecuting the steps SP3–SP7 four times, and the flow advances to stepSP8.

In step SP8, the value L of Walsh code length is doubled for updating toL=8. In step SP9, a check is made to see if the value L of Walsh codelength has become larger than the maximum value 128. If the answer isaffirmative, the flow returns to step SP2.

In step SP2, initialization is made again to i=0 and the routine ofsteps SP3–SP7 is executed. With L=8, the routine of steps SP3–SP7 isexecuted eight times. In this eight-time execution, power coefficientsρi·L and parameters ^ai·L, Δτ^i·L, Δθ^i·L, Δ^ω, τ0′ for eight channelsof 0–7 defined for Walsh code length of L=8 are calculated and arestored in the memory 33A.

In this way the Walsh code length L is updated in the order of 4, 8, 16,32, 64, and 128, and power coefficient ρi·L and parameters ^ai·L,Δτ^i·L, Δθ^i·L, Δ^ω, τ0′ are stored in the memory 33A for each channeldetermined by each Walsh code length L.

If it is detected in step SP9 that the value L of Walsh code length hasexceeded the maximum value of 128, the processing flow branches to stepSP10.

In step SP10, an electric power of each channel is calculated from, forexample, power coefficient ρi included in the measurement results ofeach channel and in accordance with an address which is determined by adesired to-be-displayed channel number set in the setting means 35, andthis power value is inputted to the graphing means 33B. The graphingmeans 33B determines the height of a bar graph to be displayed at thedisplay position of each channel correspondingly to the power value ofeach channel, and causes image data of the bar graph to be stored in theimage memory 33C. The calculation result display 33D reads the bar graphdata from the image memory 33C and displays the bar graph.

Power W can be calculated as follows from the power coefficient ρi·L:W=10.0×log₁₀(ρi·L)This calculation can be done in the graphing means 33B for example.

For example, therefore, if i=0, 1, 2, . . . 7 are set at Walsh codelength L=8 and the operation mode is set to a mode of displayingelectric powers of signals present in 0–7 channels, it is possible todisplay the electric power W of CDMA signal present on each ofeight-channel transmission lines, as shown in FIG. 4.

At this time, it is necessary that Walsh code length L be sure to beknown as L=8 with respect to the signal to be measured. Thus, the valueof Walsh code length L and the channel which outputs the signal areknown in advance, so by setting the known value in the setting means 35and if a spectrum which reflects it as it is, it can be judged that thebase station is operating normally.

As shown in FIG. 4, Walsh code length (L=8) is displayed in a numericalvalue display column 40. Parameters Δτ and Δθ (or Δτ^ and Δθ^) may bedisplayed in the numerical value display column 40, as shown in FIG. 5.The parameters Δτ and Δτ^ stand for a delay difference of each channel,while the parameters Δθ and Δθ^ stand for a phase difference of eachchannel.

Although in the example shown in FIG. 5 electric power W is displayedalong the axis of ordinate, parameters Δτ and Δθ (or Δτ^and Δθ^) may bedisplayed along the axis of ordinate.

Second Embodiment

This second embodiment is different from the first embodiment in pointof displaying a noise power component. A description will be given belowonly about the different point.

Noise power coefficient ρ_(Ni) (code Domain Error) is calculated asfollows by the power coefficient calculator 31 using Z_(j)·k and Ri·j·kin the expression (9).

The sum of channels in the ideal signal Ri is subtracted from themeasurement signal Z to obtain an error signal N, and a powercoefficient is determined as follows with respect to the error signal N:$\begin{matrix}{N_{i \cdot k} = {Z_{j \cdot k} - {\sum\limits_{i}^{L - 1}\; R_{i \cdot j \cdot k}}}} \\{\rho_{N\; i} = \frac{\sum\limits_{j = 1}^{({M/L})}\;{{\sum\limits_{k = 1}^{L}\;{N_{j \cdot k} \times R_{i \cdot j \cdot k}^{*}}}}^{2}}{\left\{ {\sum\limits_{k = 1}^{L}{R_{i \cdot j \cdot k}}^{2}} \right\}\left\{ {\sum\limits_{j = 1}^{({M/L})}{\underset{k = 1}{\overset{L}{\cdot \sum}}{Z_{j \cdot k}}^{2}}} \right\}}}\end{matrix}$

Noise power W_(N) of i channel is calculated as follows:W _(N)=10.0×log₁₀(ρ_(Ni))

The result of the calculation is stored in the memory 33A in a pair withthe signal power W_(S) channel by channel. The values of signal powerW_(S) and noise power W_(N) in each channel are graphed by a graphplotting means (included in the calculation result display 33) andwritten as a graph in an image memory. The values of signal power W_(S)and noise power W_(N) in all the channels are all stored in the imagememory, whereby the states of all the channels are displayed on thedisplay.

FIG. 6 shows an example of the plotting. In the same figure, hatchedportions (graphs) with solid lines represent signal powers W_(S) of thechannels, while dotted line portions (graphs) represent noise powersW_(N) of the channels. The height (length) of each graph represents thesignal power W_(S) and noise power W_(N) of each channel. The graphs ofnoise power W_(N) underlie vertical (longitudinal) extension lines ofthe graphs of signal power W_(S).

According to the present invention, as set forth above, the measurementof waveform quality is conducted with respect to all the channelsdefined by the CDMA signal standard and the results of the measurementare stored in the memory 33A, so that by setting in the setting means 35both Walsh code length and Walsh code given as known values from amongthe stored values for which a signal is being issued at present, then byreading a power coefficient specified by the setting means 35, as wellas parameters, and inputting the thus-read power coefficient andparameters to the calculation result display 33D, it is possible todisplay the waveform quality of the channel which is determined bydesired Walsh code length and Walsh code.

Thus, by using the system of the invention in case of adjusting, forexample, a base station for portable telephone to be tested, there canbe obtained an advantage that the time and labor required for theadjustment can be greatly reduced.

1. A multiplexed signal quality display system for measuring the qualityof a multiplexed signal issued from a communication device wherein aband width to be used and the number of communication channels capableof being accommodated are determined by a diffusion code length, thenumber of communication channels and channels to be used, which aredetermined by a diffusion code length, are decided in terms of adiffusion code number affixed to the type of the diffusion code, toeffect communication while ensuring multi-channel communication lines inone and same band, said system comprising: a memory means for storingmeasurement results obtained by measuring electric powers of signalspresent in all of the channels within the band used; and a display meanswhich specifies a channel where the presence of a signal is predictedand reads and displays a measured value in the specified channel;wherein said memory means stores an electric power of a signal and anoise component power of the signal, and said display means displays agraph having a length proportional to the values of said electric powerof the signal and a graph having a length proportional to the value ofsaid noise component power of the signal in such a manner that in alongitudinal direction of one of said graphs there is disposed the othergraph.
 2. A multiplexed signal quality display system according to claim1, wherein said memory means stores a phase difference or a delaydifference of each said channel, and said display means reads the phasedifference or the delay difference of each said channel from said memorymeans and displays it.
 3. A multiplexed signal quality display systemfor measuring the quality of a multiplexed signal issued from acommunication device wherein a band width to be used and the number ofcommunication channels capable of being accommodated are determined by adiffusion code length, the number of communication channels and channelsto be used, which are determined by a diffusion code length, are decidedin terms of a diffusion code number affixed to the type of the diffusioncode, to effect communication while ensuring multi-channel communicationlines in one and same band, said system comprising: an updating meanswhich initializes a diffusion code length and a diffusion code numberdefined for each diffusion code length and which makes updating from theinitialized values up to predetermined final values; a diffusion codegenerating means which generates a diffusion code in accordance with thediffusion code length and diffusion code number generated by saidupdating means; a demodulator means which demodulates the signal in eachsaid channel in accordance with the diffusion code generated by saiddiffusion code generating means and said diffusion code length and saiddiffusion code number; a power coefficient calculator which calculates apower coefficient of the signal demodulated by said demodulator means; amemory which stores the power coefficient of each said channelcalculated by said power coefficient calculator in accordance with thediffusion code length and the diffusion code number; a setting meanswhich reads a power coefficient from among the power coefficients storedin said memory while specifying desired diffusion code and diffusioncode number; a graphing means which converts the power coefficient readby said setting means into a power value, determines a length in Y-axisdirection in accordance with said power value, and forms a strip-likedisplay region; an image memory which stores image data graphed by saidgraphing means; and a calculation result display means which displaysthe image stored in said image memory.
 4. A multiplexed signal qualitydisplay method for measuring the quality of a multiplexed signal issuedfrom a communication device wherein a band width to be used and thenumber of communication channels capable of being accommodated aredetermined by a diffusion code length, the number of communicationchannels and channels to be used, which are determined by a diffusioncode length, are decided in terms of a diffusion code number affixed tothe type of the diffusion code, to effect communication while ensuringmulti-channel communication lines in one and same band, said methodcomprising: a storing step for storing measurement results obtained bymeasuring electric powers of signals present in all of the channelswithin the band used; and a display step which specifies a channel wherethe presence of a signal is predicted and reads and displays a measuredvalue in the specified channel, wherein said storing step stores anelectric power of a signal and a noise component power of the signal,and said display step displays a graph having a length proportional tothe values of said electric power of the signal and a graph having alength proportional to the value of said noise component power of thesignal in such a manner that in a longitudinal direction of one of saidgraphs there is disposed the other graph.
 5. A program of instructionsfor execution by the computer to perform a multiplexed signal qualitydisplay process for measuring the quality of a multiplexed signal issuedfrom a communication device wherein a band width to be used and thenumber of communication channels capable of being accommodated aredetermined by a diffusion code length, the number of communicationchannels and channels to be used, which are determined by a diffusioncode length, are decided in terms of a diffusion code number affixed tothe type of the diffusion code, to effect communication while ensuringmulti-channel communication lines in one and same band, said multiplexedsignal quality display process comprising: a storing process for storingmeasurement results obtained by measuring electric powers of signalspresent in all of the channels within the band used; and a displayprocess which specifies a channel where the presence of a signal ispredicted and reads and displays a measured value in the specifiedchannel; wherein said storing process stores an electric power of asignal and a noise component power of the signal, and said displayprocess displays a graph having a length proportional to the values ofsaid electric power of the signal and a graph having a lengthproportional to the value of said noise component power of the signal insuch a manner that in a longitudinal direction of one of said graphsthere is disposed the other graph.
 6. A computer-readable medium havinga program of instructions for execution by the computer to perform amultiplexed signal quality display process for measuring the quality ofa multiplexed signal issued from a communication device wherein a bandwidth to be used and the number of communication channels capable ofbeing accommodated are determined by a diffusion code length, the numberof communication channels and channels to be used, which are determinedby a diffusion code length, are decided in terms of a diffusion codenumber affixed to the type of the diffusion code, to effectcommunication while ensuring multi-channel communication lines in oneand same band, said multiplexed signal quality display processcomprising: a storing process for storing measurement results obtainedby measuring electric powers of signals present in all of the channelswithin the band used; and a display process which specifies a channelwhere the presence of a signal is predicted and reads and displays ameasured value in the specified channel; wherein said storing processstores an electric power of a signal and a noise component power of thesignal, and said display process displays a graph having a lengthproportional to the values of said electric power of the signal and agraph having a length proportional to the value of said noise componentpower of the signal in such a manner that in a longitudinal direction ofone of said graphs there is disposed the other graph.